Excellent article overall, but this point seems true whether the "you" referred to is a boy or a girl. And it's certainly true that a lot of girls naturally identify with the girls. (Also true that a lot don't identify that much except as demanded by social constraints--so it wouldn't make sense to conclude it's true of all girls.)

Thus, if this argument is valid, many women/girls ought to have the corresponding gender identity. Just because it's not constantly stressed and challenged doesn't necessarily mean it's not there, just like an American might very much have American identity but not really notice until they move to Japan.